/**
 * \file spinlock.h
 * \brief Simple multiporcessor safe spinlock
 * \author Corey Tabaka
 */

/*
   Copyright 2005 Corey Tabaka

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

#include <ktypes.h>

#ifndef __KERNEL_SPINLOCK_H__
#define __KERNEL_SPINLOCK_H__

#ifdef __cplusplus
extern "C" {
#endif

/**
 * Spinlock type.
 */
typedef volatile int spinlock_t;

/**
 * \def SPINLOCK_UNLOCKED
 * \brief Unlocked value of a spinlock
 */
#define SPINLOCK_UNLOCKED 0

/**
 * \def SPINLOCK_LOCKED
 * \brief Locked value of a spinlock
 */
#define SPINLOCK_LOCKED 1

void __attribute__ ((regparm(1))) spinlock_init(spinlock_t*);
int __attribute__ ((regparm(1))) spinlock_wait(spinlock_t*);
void __attribute__ ((regparm(1))) spinlock_signal(spinlock_t*);
int __attribute__ ((regparm(1))) spinlock_try(spinlock_t*);

#ifdef __cplusplus
}
#endif

/*
 * Interrupt Mutexes
 */
#define INT_MUTEX_UNLOCKED { SPINLOCK_UNLOCKED, 0 }

typedef struct {
	spinlock_t spinlock;		// must be the first element in the structure
	uint32 flag __attribute__((packed));
} int_mutex_t;

#ifdef __cplusplus
extern "C" {
#endif

void __attribute__ ((regparm(1))) interrupt_mutex_init(int_mutex_t *);
void __attribute__ ((regparm(1))) interrupt_mutex_wait(int_mutex_t *);
void __attribute__ ((regparm(1))) interrupt_mutex_signal(int_mutex_t *);

#ifdef __cplusplus
}
#endif

#endif
